Algorithms Research And System Realization Of GNSS/MIMU Integrated Navigation

At present,GNSS / MIMU integrated navigation system performance is difficult to meet the requirements of low-cost and high-precision,this paper systematically studies GNSS/MIMU integrated navigation algorithm and sy stem implementation.Including MIMU error theory analysis,GNSS/MIMU integrated navigation method,additional constrained GNSS/MIMU integrated navigation fusion algorithm,additional constraints GNSS/MIMU integrated navigation system implementation and so on.Summarized as follows:1.Complementary Ensemble Empirical Mode Decomposition(CEEMD)threshold filter based on sample entropy and similarity index.Using Allan Variance and Davar Method to Identify the Noise Characteristics of Micro-Electro-Mechanical System(MEMS)Gyroscope,By using the linear index of sample entropy and similarity,the Intrinsic Mode Function(IMF)is decomposed by CEEMD and the threshold of each IMF is constructed according to the noise figure of the gyroscope,in order to reduces the noise of the MEMS gyroscope.The simulation and experimental data show that this method can effectively reduce the noise of MEMS gyroscope.2.Carrier double-differential loosely coupled and pseudorange double-differential tightly coupled for GNSS/MIMU integrated navigation is deduced,and the error of GNSS/MIMU is adopted to reduce the error contained by GNSS observation and improve the accuracy of combined navigation.The measured data show that the carrier double-differential loosely coupled and the pseudorange double-differential tightly coupled are improved by an order of magnitude compared with the GNSS pseudorange elastic combination navigation position accuracy.The measured data show that the carrier double differential loosely coupled and the pseudorange double differential tightly coupled are improved by an order of magnitude compared with the GNSS pseudorange elastic combination navigation position accuracy.3.Espablish the GNSS/MIMU integrated navigation algorithm with additional constraints.When GNSS is valid,the validity of single antenna attitude measurement and dual antenna orientation constraint is demonstrated.the measured data show that the GNSS attitude constraints can improve the attitude accuracy of the system effectively,and the double antenna direction finding can improve the initialization efficiency of the integrated navigation system.When GNSS is invalid,the fusion algorithm of additional elevation constraint,barometer constraint,attitude constraint and dynamic zero speed correction is deduced.the measured data show that the additional motion and external sensor information constraints can reduce the error accumulation improve the navigation accuracy when the GNSS is invalid.4.Develope principled sample machine of GNSS/MIMU integrated navigation system with additional constraints.According to the system requirements,select the appropriate MIMU inertial devices,OEM boards and processors as the core integrated system hardware platform.Based on the hardware platform to write additional constrained GNSS/MIMU integrated navigation algorithm to complete the principled sample machine development.Finally,the static test and the dynamic test results showed that the system positioning accuracy had reached the requirement.